Fate of vital pulps beneath a metal-ceramic crown or a bridge retainer

By Cheung GS, Lai SC, Ng RP

Date: 03/2005
Journal: IEJ


Purpose:to investigate the incidence and the factors that might be associated with the development of pulpal necrosis in vital abutment teeth that had been crowned either singly or as part of a fixed bridge.


  • The study population consisted of patients who had received a CMC or a conventional fixed bridge on vital tooth/teeth from 1981 to 1989

•122 Metal-Ceramic Crowns and 47 bridges (77 vital abutments ) were included

•Inclusion criteria : teeth  without RCT prior construction of the restoration and teeth received CMC or bridges

•Patients were invited to return for a review after reviewing their records for:  preexisting DMFT score, presence of dental pins or pulp capping, status of the preexisting restoration, the reason for crown/bridge construction. However,  only the endodontic reason was considered which  is the abutment tooth became pulpally or periapically involved, or had been root filled after restoration

•Most highlighted Results :

•All teeth that presented with pulpal symptoms at the review also showed a periapical radiolucent lesion or had been root-filled , they were classified as failures due to endodontic reason.

•Metal-ceramic crowns : out of 122 , 19 ( 16 %)  have failed due to endodontic origin .

•Bridges : out of 47 bridges (77 vital abutments ) , 22 had at least one of their abutments affected by some form of pulpal or endodontic complications  .

•Survival rates for pulp vitality were estimated to be 84.4% (CMC) and 70.8% (BR) after 10 years, and 81.2% (CMC) and 66.2% (BR) after 15 years •Significantly greater amount of bridge abutments developed pulp necrosis than CMC

•An association was found between pulpal necrosis and tooth type with maxillary anterior teeth being most often affected

•Clinical significance :

 Vitality of abutment teeth of conventional bridges should be examined frequently in order to prevent endodontic complication